This invention relates to a rotary die cutting system which is fed by web stock and more particularly to a system for reducing the scrap material produced by rotary die cutters between successive blanks treated or cut from the web.
In conventional rotary die cutter systems, wherein the web stock is fed by powered pull rolls operating in synchronism with the die and anvil cylinders, the web is fed intermittently to maintain approximately the same accumulated loop of web material.
One of the problems with this conventional technique is that after the trailing edge of the die, which includes a cut-off knife, has cut off the portion of the web which passed between the die and the anvil cylinders, momentum tends to feed the cut edge of the web forward so that there will be a substantial area of the web lying beyond the point at which the leading end of the die will again strike the web. All of the material in advance of the line where the die will make contact during the next cycle will be scrap.
Accordingly, there is a need for a mechanism which when combined with a rotary die cutter, reduces the amount of web material which lies beyond the point where the leading edge of the die, upon rotation of the circular die cutter, strikes the web, and thereby reduces the amount of scrap web material produced.